Reenforced mine prop



M. J. CONWAY y RBENFORCEDMINE PROP` Filed June s.'V 1926 WITNESSES TN nEWG, MJU

ATTORNEYS Patented` Sept. 13, 1927.

uNrrlezDv STATES MARTIN J. CONWAY, OF STUBENVILLE, OHIO.

REENFORCED .MINE PROP.

Application led June 3,

My invention relates to a mine prop, particularly to a metal mine prophaving a reenforcingA core or interior of Wood.

The general object of my invention is to provide a mine prop possessingincreased strength over a Wooden prop of equal cross sectional area.

The distinguishing features and advantages of my improved mine prop Willclearly appear as the description proceeds.

y Reference is to be had to the accompanying drawingsforming a part ofthis specification, it being understood that the ydrawings are merelyillustrative of one example ofthe invention.

Figure 1 is a longitudinal sectional view of a mine prop embodying myinvention Y Figure 2 is a cross section on the line 2-2, Figure 1. Y Incarrying out my invention in accordance With the illustrated example, alength of pipe 10 is provided of the desired diameter according to thefinal dimensions required in the particular prop. Within the pipe 10 isa central turned hard-Wood core 11 terminating at its ends short of theends of the pipe 10. The prop is completed by means of two turnedhard-Wood end plugs 12 having tenons 13 or inner ends of reduced `30diameter having a driving lit in the ends of the pipe 10. A shoulder 14on each plug is poduced at the base of thereduced inner end 192e..serial No. 113,540.

or tenon 13 sovthat the outer portion of larger diameter abuts at saidshoulders against the ends of the pipe 10. The length of the tenonsorreduced inner ends 13 is such that the plugs complete with the centralcore 11 a solid reenforcement for the complete length of the pipe 10.

The pipe 10 is inpractice made of steel 4o and constitutes a casing forthe major portion of the length of the prop and with the reenforcementprovided by the core 11 and end plugs as described, strength is obtainedmaterially beyond a prop made of Wood as i demonstrated by actual trial.Y

I Would state furthermore that While the illustrated example constitutesa practical embodiment of my invention,` I do not limit myself strictlyto the exact details herein illustrated, since, manifestly, the same canloe considerably varied Without departure from the spirit of theinvention as defined in the appended claim.

Having thus described my invention, I claim:

As an article of manufacture, a mine prop having a metal casing, acentral hard-Wood core in said casing and terminating short of the endsthereof, and plugs having tenons, said tenons having a driving fit inthe ends' lof said casing and extending inward to the ends of said core.

MARTIN J. CONWAY.

